Intake device for an internal combustion engine and method thereof

Abstract

An intake device of an internal combustion engine is provided that includes an intake flow control valve shaped so as to be capable of effectively forming a tumble flow within a combustion chamber when there is a projection within an intake pipe located downstream of the intake flow control valve. The intake device of the internal combustion engine includes an intake flow control valve between a throttle valve provided within an intake pipe and a fuel injector located downstream of the throttle valve, for producing a tumble flow in a combustion chamber. The intake flow control valve includes a valve body. The valve body has a bypass airflow producing portion formed at a position corresponding to that of the fuel injector (i.e., a projection within the intake pipe) when viewed in a flow direction of the airflow. The valve body is shaped to have a projection, thereby allowing an airflow formed by the intake flow control valve to bypass the projection within the intake pipe located downstream of the intake flow control valve.

What is claimed is:  
     
       1. An intake device of an internal combustion engine, comprising: 
       a throttle valve provided within an intake pipe;  
       a projection within the intake pipe located downstream of the throttle valve; and  
       an intake valve provided between the throttle valve and the projection within the intake pipe that produces a tumble flow in a combustion chamber, wherein:  
       the intake valve is shaped so that an airflow, formed by the intake valve, bypasses the projection located downstream of the intake valve, and a projected area of the bypass located on a valve body of the intake valve as viewed in the flow direction of the airflow in the intake pipe is smaller than a projected area of the projection as viewed in the flow direction of the airflow in the intake pipe.  
     
     
       2. The intake device according to  claim 1 , wherein the shape of the intake valve is set according to a position and shape of the projection within the intake pipe and a distance from the projection to the intake valve. 
     
     
       3. The intake device according to  claim 1 , wherein the projection within the intake pipe is located in a center of a top of the intake pipe in cross section, and the intake valve has a convex shape having portions removed at both upper side ends of the intake valve. 
     
     
       4. The intake device according to  claim 1 , wherein an outer edge of the intake valve is formed from a smooth connection of a straight edge and a curved edge. 
     
     
       5. An intake device of an internal combustion engine, comprising: 
       an intake pipe that passes an airflow therethrough into the internal combustion engine;  
       a throttle valve provided within the intake pipe;  
       a projection within the intake pipe located downstream of the throttle valve; and  
       an intake valve provided between the throttle valve and the projection within the intake pipe, wherein:  
       a lower portion of a valve body of the intake valve is shaped so as to correspond to an oblique cross-sectional shape of the intake pipe, and an upper portion of the valve body has notches; and  
       a bypass is located on said valve body corresponding to a position of the projection when viewed in a flow direction of the airflow in the intake pipe,  
       wherein the bypass causes the airflow passing through the intake valve to bypass the projection, and a projected area of the bypass as viewed in the flow direction of the airflow in the intake pipe is smaller than a projected area of the projection as viewed in the flow direction of the airflow in the intake pipe.  
     
     
       6. The intake device according to  claim 5 , wherein a width of the bypass is variably set in proportion to a width of the projection as viewed from the flow direction of the airflow in the intake pipe. 
     
     
       7. The intake device according to  claim 5 , wherein the bypass is sized in inverse proportion to a distance between the projection within the intake pipe and the intake valve. 
     
     
       8. The intake device according to  claim 5 , further comprising a combustion chamber provided downstream of the projection, wherein the bypass is sized in inverse proportion to a distance between the projection within the intake pipe and the combustion chamber. 
     
     
       9. The intake device according to  claim 5 , wherein an outer edge of the valve body is formed from a smooth connection of a straight edge and a curved edge. 
     
     
       10. The intake device according to  claim 5 , further comprising a straightening plate provided within the intake pipe, the straightening plate extending in the flow direction of the airflow, and abutting respective horizontal ends of the notches of the valve body when the intake valve is in a fully closed state. 
     
     
       11. The intake device according to  claim 10 , wherein an outer edge of the straightening plate is formed from a smooth connection of a straight edge and a curved edge. 
     
     
       12. A method for controlling an airflow into an internal combustion engine having an intake device including a throttle valve provided within an intake pipe; a projection within the intake pipe located downstream of the throttle valve; and an intake valve provided between the throttle valve and the projection within the intake pipe, the method comprising: 
       producing a tumble flow in a combustion chamber with the intake valve; and  
       shaping the intake valve such that an airflow across the intake valve bypasses the projection located downstream of the intake valve, wherein the shape of the intake valve is set according to a position and shape of the projection and a distance from the projection to the intake valve.